套筒式陶瓷燃烧器内燃烧过程数学模型

应用湍流扩散火焰燃烧模型，对套筒式陶瓷燃烧器燃烧室内的燃烧过程进行了计算机模拟研究，确定了燃烧过程中煤气空气及燃烧产物的速度分布，温度２和各组分的浓度分布，得到了燃烧过程中火焰的形状和长度。     

蓄热式钢包烘烤热行为的数值模拟和[NOx]排放特性

为了研究蓄热式钢包烘烤的空气和煤气的预热温度对高温空气燃烧过程的影响,耦合了烘烤过程中流体流动、换热和燃烧过程,用数值模拟方法建立了三维立体数学模型,利用计算流体力学软件Fluent,采用有限元差分法和修正速度—压力相耦合的算法Simple,计算了钢包内的燃烧现象,得出了在不同预热温度时,燃烧室内气体温度场和氧气浓度场的分布。结果表明,提高气体预热温度有利于加快燃烧进程,可提高炉内的整体温度及温度的均匀性,降低局部氧浓度,利用高的烘烤效率减少[NOx]的排放。     

不同助燃条件下超音速火焰喷涂的燃烧特性

运用FLUENT软件,在气体-颗粒两相流基础上,计算了纯氧气、空气、氧-空气联合助燃3种情况下超音速火焰喷涂的燃烧特性.结果表明:纯氧气助燃时燃烧充分,焰流温度高,但氧气质量流量增加对焰流温度影响很小;空气助燃时所用空气流量大,导致燃烧室压力大,故适宜喷涂低熔点、易氧化粉末材料;氧-空气联合助燃时,氧气含量越大,焰流能达到的最高温度越高,但当氧气含量达到一定比例后可完全替代纯氧助燃;助燃气体中氧气含量的不同间接影响燃烧产物成分分布.     

氧甲醇汽油火焰燃烧性能分析与切割试验

根据热力学理论分析和讨论了氧甲醇汽油的燃烧过程,分析火焰燃烧时各区域的产热及其能量平衡关系,计算了甲醇在不同混合比例下的火焰燃烧理论温度。根据当前国内甲醇汽油的应用情况,提出利用氧甲醇汽油作为金属氧气切割方法的新型燃料。通过一系列切割试验表明,氧甲醇汽油在甲醇比例为10%~50%范围时,火焰燃烧稳定,切割质量优良,能满足普通钢材的火焰切割要求。     

压铸件侧凹特征的识别

侧凹特征的识别影响着分模方向、分型线和分型面的确定,以及型芯与型腔镶块的产生、局部成形工具的构造及它们的运行机制.最佳分模方向的确定有赖于侧凹特征的识别.因此,在整个模具设计过程中,侧凹特征的识别必须在其他一切设计活动之前完成.介绍了侧凹特征的定义,建立了侧凹特征库,研究和实现了基于面属性邻接图的压铸件侧凹特征识别.     

氧乙醇汽油火焰燃烧分析及切割试验

根据热力学理论,通过分析氧乙醇汽油的燃烧过程、各区域的产热及其能量平衡关系,计算了乙醇在不同混合比例下的火焰燃烧理论温度.根据当前国内车用乙醇汽油的实际应用情况,提出了利用氧乙醇汽油火焰切割金属的新方法.利用专用割嘴进行一系列切割试验后表明,氧乙醇汽油在乙醇比例为10％～50％范国内火焰燃烧稳定,能满足普通钢材的火焰切割要求,通过在辽宁石油化工大学本科生实践教学的应用,证明切割质量优良,具有很好的节能性和安全性.     

预热温度对热风炉燃烧特性影响的数值模拟

提高风温是高炉炼铁节能降耗的重要技术措施,用CFX模拟不同助燃空气预热温度条件下的燃烧状态,研究结果表明,提高助燃空气预热温度可使燃烧室内的速度场更加均匀,火焰减短,高温区向下扩展,但对燃烧效率没有影响,为迁安2号高炉热风炉实现1 280℃高风温提供理论依据。     

氧乙醇火焰燃烧性能及其切割性分析

按热力学理论讨论了氧乙醇的燃烧过程,分析火焰燃烧时各区域的产热及其能量平衡,计算火焰理论温度,提出氧乙醇火焰可以作为金属氧气切割方法的热源.通过切割试验,证明该方法可行,并且切割质量优良.     

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 提高风温是高炉炼铁节能降耗的重要技术措施,本文采用CFX模拟不同助燃空气预热温度条件下的燃烧状态,研究结果表明提高助燃空气预热温度可使燃烧室内的速度场更加均匀,火焰减短,高温区向下扩展,但对燃烧效率没有影响,为迁安2号高炉热风炉实现1280℃高风温提供理论依据。     

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 通过建立圆管状燃烧室内甲烷气体燃烧的数学模型,对燃烧室回流区的温度场、速度场、流场以及甲烷、氧气、二氧化碳以及氮氧化合物的质量分数进行了数值模拟。通过改变入口高温空气的预热温度,数值模拟了以上变量的分布规律。研究结果表明,提高空气的预热温度,燃烧室内的反应进行越彻底,温度分布更均匀。研究结果对燃烧室的设计和燃烧室工况分析具有指导意义,所建立的数学模型为燃烧室几何和结构设计和燃烧过程操作中进行定量分析的有效手段。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.